That 'ultra-precise machining' does have some advantages, though:
InRangeTV simulated whether a weapon will still work if it gets covered in mud. Originally they tried doing this buy having a guy crawl around in the mud; later, they realised they could just drop mud on the weapon.
AKM https://www.youtube.com/watch?v=DX73uXs3xGU
AR-15 ("This AR15 mud test was performed right after last week's AK47 test: the same exact mud, the same wheelbarrow, at the same location, a mere 10 minutes later.") https://www.youtube.com/watch?v=YAneTFiz5WU
Incidentally, InRangeTV's videos have been used in both Russian & Ukranian propaganda https://www.youtube.com/watch?v=PtRjBRRL2LY
We're I equipping a small army, I would look into something like the galil which mixes the best features of the AK (easy to manufacture lower receiver and reliability) with the best features of US weapon systems (accuracy at 300-500m). And the bottle opener on the front handguard is a definite plus.